8344675908
This is a Clang-only change and depends on the existing "musttail" support already implemented in LLVM. The [[clang::musttail]] attribute goes on a return statement, not a function definition. There are several constraints that the user must follow when using [[clang::musttail]], and these constraints are verified by Sema. Tail calls are supported on regular function calls, calls through a function pointer, member function calls, and even pointer to member. Future work would be to throw a warning if a users tries to pass a pointer or reference to a local variable through a musttail call. Reviewed By: rsmith Differential Revision: https://reviews.llvm.org/D99517
27 lines
857 B
Objective-C
27 lines
857 B
Objective-C
// RUN: %clang_cc1 -fsyntax-only -fblocks -Wno-objc-root-class -verify %s
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void TestObjcBlock(void) {
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void (^x)(void) = ^(void) {
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__attribute__((musttail)) return TestObjcBlock(); // expected-error{{'musttail' attribute cannot be used from a block}}
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};
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__attribute__((musttail)) return x();
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}
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void ReturnsVoid(void);
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void TestObjcBlockVar(void) {
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__block int i = 0; // expected-note{{jump exits scope of __block variable}}
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__attribute__((musttail)) return ReturnsVoid(); // expected-error{{cannot perform a tail call from this return statement}}
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}
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__attribute__((objc_root_class))
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@interface TestObjcClass
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@end
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@implementation TestObjcClass
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- (void)testObjCMethod {
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__attribute__((musttail)) return ReturnsVoid(); // expected-error{{'musttail' attribute cannot be used from an Objective-C function}}
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}
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@end
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